darts

Abstract

The dart 10 comprises, in order from the tip side to the base side, a tip 11, a barrel 12, and a shaft 13. The shaft 13 gradually reduces in diameter from the tip side to the base side. Three flights 14 are attached and fixed to the base side of the shaft 13 at equal angular positions centered on the axis of the shaft 13. The base sides of the flights 14 protrude from the shaft 13 and are connected to each other. The shaft 13 has grooves 18 formed between adjacent flights 14 in the circumferential direction of the shaft 13. The inner width of the groove 18 gradually increases from the flight 14 side toward the center of the shaft 13 in the axial direction, and gradually decreases from the center of the shaft 13 in the axial direction toward the barrel 12 side.

Description

Technical Field

[0001] The present invention relates to darts used in a sports toy in which points are competed by throwing at a target (dart board) installed on a wall or the like.

Background Art

[0002] Darts competitions are widely developed with professional competitions being held as sports competitions for competing for points. Specifically, it is a competition in which darts (arrows, darts) are thrown at a target and the high score in the center part thereof is competed, and what is competed is how many darts can be thrown into the center of the target. Therefore, it is a competition that requires stabbing the darts as concentrated as possible into the center of the target. Conventionally, for example, darts disclosed in Patent Documents 1 to 3 are known. However, when such darts are thrown, since the previously thrown dart is stuck in the target and then the next dart is continuously thrown, the dart thrown later may collide with the dart already stuck in the target and be bounced off, and the dart may not be stuck at the same position. In addition, the dart already stuck in the target may be bounced off and separated from the target. Therefore, the present inventors have proposed the darts disclosed in Patent Document 4.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0004] With the darts described above, it is possible to suppress more than conventionally the situation where a later - thrown dart collides with a dart already stuck in the target and bounces off, or the situation where a dart already stuck in the target is knocked away by a later - thrown dart. However, further improvement is desired.

[0005] The present invention has been made in view of such circumstances, and an object thereof is to provide darts capable of suppressing, and further preventing, the situation where a later - thrown dart collides with a dart already stuck in the target and bounces off, or the situation where a dart already stuck in the target is knocked away by a later - thrown dart, more than conventionally.

Means for Solving the Problem

[0006] The darts according to the present invention that meet the above object are darts that sequentially include a tip, a barrel, and a shaft from the tip side to the base side. The shaft gradually decreases in diameter from the tip side to the base side. On the base side of the shaft, three flights are attached and fixed at equal angular positions around the axis of the shaft. Moreover, the base sides of the flights protrude from the shaft and are connected to each other. A groove is formed in the shaft between the adjacent flights in the circumferential direction of the shaft. The inner width of the groove gradually widens from the flight side toward the central portion of the shaft in the axial direction, and gradually narrows from the central portion of the shaft in the axial direction toward the barrel side.

[0007] In this way, since the number of flights is three and they are attached and fixed to the shaft at equal angular positions (positions at 120 - degree intervals) around its axis, the interval between adjacent flights in the circumferential direction of the shaft can be made wider than in the case where the number of flights is four (positions at 90 - degree intervals). Therefore, when continuously throwing darts, it becomes difficult for a later - thrown dart to collide with the flights of a dart already stuck in the target. Also, since the shaft has a shape that gradually decreases in diameter from the tip side to the base side, and the base sides of the flights protrude from the shaft and are connected to each other, it becomes difficult for a later - thrown dart to collide with the shaft of a dart already stuck in the target, and even if a collision occurs, it can smoothly pass through. Furthermore, grooves are formed in the shaft between the flights adjacent to each other in the circumferential direction. By setting the number of flights to three, the cross-sectional area per groove (the area on a plane perpendicular to the axial direction of the shaft) can be made larger than in the case where the number of flights is four, so that the above-described effects can be further enhanced. Note that the inner width of the groove gradually widens from the flight side to the barrel side in the axial direction of the shaft and then gradually narrows, so that without impairing the strength of the shaft, even when the tip of the dart thrown later collides with the dart already stuck in the target, it can smoothly slip through.

[0008] Here, it is preferable that the depth of the groove gradually increases from the flight side toward the center in the axial direction of the shaft and gradually decreases from the center in the axial direction of the shaft toward the barrel side. Moreover, it is preferable that the three grooves have the same shape and are formed at equiangular positions around the axis of the shaft. Furthermore, the shaft can be detachably attached to the barrel.

Advantages of the Invention

[0009] The dart according to the present invention, for example, when throwing a plurality of darts in succession, makes it less likely for the dart thrown later to collide with the flight of the dart already stuck in the target, and even when the tip of the dart thrown later collides with the dart already stuck in the target, it can smoothly slip through. Therefore, compared with conventional darts, the dart thrown later is not greatly deflected by the dart already stuck in the target and can be stuck in the target near this dart, or the dart already stuck in the target can be prevented from being deflected and separated from the target by the dart thrown later more effectively than in the prior art. Therefore, it is possible to achieve a high score in competitions and the like.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0011] Subsequently, with reference to the accompanying drawings, embodiments of the present invention will be described to facilitate understanding of the present invention. As shown in FIGS. 1 to 4, a dart 10 according to an embodiment of the present invention sequentially includes a tip (also referred to as a point) 11, a barrel 12, and a shaft 13 from the tip side (front side) to the base side (rear side). A flight 14 is attached and fixed to the base side of the shaft 13. When throwing a plurality of darts 10 in succession, it is possible to suppress and further prevent a dart 10 thrown later from colliding with and bouncing off a dart 10 that has been previously thrown and stuck in a target (not shown), or from causing a dart 10 that has been stuck in the target to be bounced off by a dart 10 thrown later, more effectively than in the prior art. Details will be described below.

[0012] As shown in FIG. 1, the tip 11 is provided at the front portion in the axial direction of the dart 10 and is the portion that pierces the target. This tip 11 is, for example, made of metal or plastic and can be detachably (replaceably) attached to the barrel 12 by means of a threaded portion or the like (not shown).

[0013] As shown in FIG. 1, the barrel 12 is provided at the central portion in the axial direction of the dart 10, and when throwing the dart 10, it is common to hold this barrel 12. This barrel 12 is mainly made of metal, heavy, and effective for throwing the dart 10 far. The materials of the barrel 12 are various, such as brass, nickel alloy, tungsten alloy, etc. However, those made of tungsten alloy or nickel alloy with a high specific gravity are thinner and less likely to interfere when hitting the target. In addition, the barrel 12 has various shapes, anti-slip grooves, weights, etc.

[0014] As shown in FIGS. 1 to 5, the shaft 13 is provided at the base in the axial direction of the dart 10. A flight 14 is attached and fixed to the base side of the shaft 13, which is a part that exerts an effect for the dart 10 to fly straight. That is, the flight 14 is a part that serves as a wing. This shaft 13 has a circular cross-section, and its diameter gradually decreases from the tip side to the base side in the axial direction (it is tapered). It can be screwed and fixedly attached (exchangeably) to the base end of the barrel 12 by a screw portion (male screw) 15 provided at its tip. The maximum diameter D of the shaft 13 (the diameter of the tip excluding the screw portion 15) is, for example, about 4.5 mm to 6.5 mm, and the axial length L1 of the shaft 13 (the length excluding the screw portion 15) is, for example, about 45 mm to 60 mm, but it is not particularly limited.

[0015] For the material of the shaft 13, various materials such as metal, resin (plastic), polycarbonate, carbon composite, etc. can be used, and it is not particularly limited as long as the above effects can be exerted. Here, it is preferable that the shaft 13 and the flight 14 are integrally formed (formed into an integral structure) by injection molding using the same resin material. However, the shaft and the flight can also be separately molded and combined. In this case, a cut is made on the base side of the shaft, and the flight can be inserted into this cut for attachment and fixation. Note that the materials of the shaft and the flight may be the same or different.

[0016] On the base side of the shaft 13, three flights 14 are attached and fixed (formed) at equiangular positions around the axis of the shaft 13. Here, the equiangular positions are positions at 120-degree intervals around the axis of the shaft 13. However, due to manufacturing errors or the like, for example, even if there is a deviation within a range of about ±1 degree (a range of 119 degrees to 121 degrees), it is included in the equiangular positions. The tip side of the flight 14 is attached and fixed to the outer periphery from the center in the axial direction of the shaft 13 to the base side. The base side of the flight 14 protrudes outward (rearward) from the shaft 13 in the axial direction of its base side and is connected to each other. Therefore, as shown in FIG. 4, when the dart 10 is viewed from the rear of the dart 10, the three flights 14 are radially arranged around the axis of the dart 10. The attachment length of the flight 14 to the shaft 13 is, for example, about 50% or more and 80% or less (preferably 60% or more) of the length L2 of the flight 14 along the axial direction of the shaft 13. The height H of the flight 14 with respect to the axis of the shaft 13 is about 15 mm to 25 mm. Also, the length L3 of the shaft 13 in the axial direction where the flight 14 is not attached is about 20 mm to 30 mm, but it is not particularly limited.

[0017] The three flights 14 have the same shape. For example, they can be in the shapes of standard, shape (halos shape), kite, teardrop, slim, etc. The outer peripheral contour of each flight 14 is, as shown in FIG. 2, along the axial direction of the shaft 13, from its tip side to the base side, composed of a curved surface where a tip-side slope 16 with a gentle inclination angle and a base-side slope 17 with a steeper inclination angle than the tip-side slope 16 are connected. Specifically, the radius of curvature R1 of the rising part constituting the tip-side slope 16 is about 8 mm to 13 mm. The base-side slope 17 rises at about 58 degrees to 65 degrees with respect to the axis. The radii of curvature R2, R3, and R4 from the tip-side slope 16 to the base-side slope 17 are respectively, R2 is about 17 mm to 21 mm, R3 is larger than R2 and about 27 mm to 33 mm, and R4 is smaller than R2 and about 4 mm to 7 mm, but it is not particularly limited. Also, the thickness of the flight 14 is usually about 0.3 mm to 0.5 mm, and the length L4 to the base end of the flight 14 including the length L1 of the shaft 13 is, for example, about 65 mm to 75 mm, but is not particularly limited.

[0018] On the shaft 13, grooves 18 are formed (a total of three) between the flights 14 adjacent to each other in the circumferential direction of the shaft 13. Each groove 18 is formed at an equal angular position around the axis of the shaft 13. Here, the equal angular position is a position at intervals of 120 degrees around the axis of the shaft 13, but due to manufacturing errors or the like, for example, even if it deviates within a range of about ±1 degree (range of 119 degrees to 121 degrees), it is included in the equal angular position. The grooves 18 are set in terms of their shape, inner width, and depth so that the dart 10 thrown later can smoothly pass through even if it collides with the dart 10 stuck in the target without impairing the strength of the shaft 13. The three grooves 18 have the same shape, and their inner width gradually widens (in an inverted taper shape) from the flight 14 side (the position where the three flights 14 are connected to each other) toward the center in the axial direction of the shaft 13, and gradually narrows (in a taper shape) from the center in the axial direction of the shaft 13 toward the barrel 12 side (in the region where there is no flight 14 in the axial direction of the shaft 13). Also, the depth of each groove 18 gradually increases from the flight 14 side toward the center in the axial direction of the shaft 13, and gradually decreases from the center in the axial direction of the shaft 13 toward the barrel 12 side (in the region where there is no flight 14 in the axial direction of the shaft 13).

[0019] The barrel 12 - side end and the flight 14 - side end of the groove 18 described above are each in an acute - angled (V - shaped) form. Since the position where the inner width of this groove 18 is the largest is at the center in the axial direction of the shaft 13 on the barrel 12 side (in the region where there is no flight 14 in the axial direction of the shaft 13), the flight 14 - side end of the groove 18 is sharper (more acute - angled) than the barrel 12 - side end. Note that the maximum inner width of the groove 18 is, for example, about 3 mm to 5 mm, but is not particularly limited. In addition, as shown in FIGS. 4 and 5, the bottom surface of the groove 18 has a cross-sectional arc shape (curve: for example, a curvature radius of about 0.4 mm to 0.6 mm). The position where the depth of the groove 18 is maximum is at the center in the axial direction of the shaft 13 on the barrel 12 side (the region where the flights 14 do not exist in the axial direction of the shaft 13). Note that the position where the inner width of the groove 18 is maximum and the position where the depth is maximum may be the same or different.

[0020] As described above, the dart 10 has three flights 14, the shaft 13 has a shape in which the diameter gradually decreases from the tip side to the base side, and further, the groove 18 having the above-described configuration is formed between the adjacent flights 14 in the circumferential direction of the shaft 13. Therefore, when throwing a plurality of darts 10 continuously, the tip of the chip 11 of the later-thrown dart 10 does not collide with the base end of the shaft 13 of the dart 10 that has hit the target, and the later-thrown dart 10 will not be deflected and will hit near the dart 10 that has hit the target. In addition, it is possible to suppress and further prevent the dart 10 that has hit the target from being deflected by the later-thrown dart 10 more effectively than before.

[0021] As described above, the present invention has been described with reference to one embodiment. However, the present invention is not limited to the configuration described in the form of the above-described embodiment, and includes other embodiments and modifications that can be considered within the scope of the matters described in the claims. For example, when configuring the dart of the present invention by combining a part or all of the above-described examples and modifications, it is also included in the scope of the rights of the present invention. In the above embodiment, the case where the shaft can be detachably attached to the base end portion of the barrel by a screw portion provided at the tip end portion thereof has been described. However, the shaft may be configured to be non-removable from the barrel.

Industrial Applicability

[0022] According to the darts of the present invention, when throwing a plurality of darts continuously, it is possible to suppress and even prevent, more than before, the situation where a later-thrown dart collides with a dart stuck in the target and bounces off, or the situation where a dart stuck in the target is bounced off by a later-thrown dart. Therefore, in competitions and the like, it is possible to achieve high scores, and for example, it has industrial applicability such as being able to contribute to the improvement of the manufacture and sale of darts.

Explanation of Signs

[0023] 10: Dart, 11: Chip, 12: Barrel, 13: Shaft, 14: Flight, 15: Threaded portion, 16: Tip-side inclined surface, 17: Base-side inclined surface, 18: Groove

Claims

1. A dart having a tip, a barrel, and a shaft in that order from the tip to the base. The shaft is gradually tapered from the tip to the base, and three flights are attached and fixed to the base of the shaft at equal angular positions around the axis of the shaft, and the base sides of the flights protrude from the shaft and are connected to each other, A groove is formed in the shaft between adjacent flights in the circumferential direction of the shaft, and an inner width of the groove gradually increases from the flight side toward the axial center of the shaft, and gradually decreases from the axial center of the shaft toward the barrel side.

2. 2. The dart according to claim 1, wherein the depth of the grooves becomes gradually deeper from the flight side toward the center of the shaft in the axial direction, and gradually becomes shallower from the center of the shaft in the axial direction toward the barrel side.

3. 3. The dart according to claim 1, wherein the three grooves have the same shape and are formed at equal angular positions around the axis of the shaft.

4. 4. The dart according to claim 3, wherein the shaft is detachably attached to the barrel.

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